Research
Stability analysis of a landing gear mechanism with torsional degree of freedom
In this study, stability of a landing gear mechanism with torsional degree of freedom is analyzed. Derivation of the equations of motion of the model with torsional degree of freedom and the von Schlippe tire model are presented. Nonlinear model is linearized and Routh-Hurwitz criterion is applied. Stability analysis is conducted in the e-v plane for different values of the torsional spring rate c and in the k-v plane for different values of the relaxation length σ and vertical force Fz . Percentages of the stable regions are computed. Effects of the variation of the caster length e, half contact length a and their ratio on stable regions are analyzed. Results and conclusions about the variation of stability are presented and constructive recommendations are given.
On dynamics of a landing gear mechanism with torsional freeplay
In this study, dynamics of a landing gear mechanism with torsional degree of freedom and torsional freeplay is analyzed. Derivation of the equations of motion of the model with torsional degree of freedom and the von Schlippe tire model are presented. Freeplay is introduced into the model and effects of freeplay angles of 0 º, 0.5º, 1º and 1.5º are observed by obtaining time histories of the torsion angle and lateral tire deformation and limit cycles of the torsionangle. Amplitudes and frequencies of oscillations of the time histories of the torsion angle and lateral tire deformation are presented.
